1. Field of the Invention
This invention relates to medical devices, and more particularly to a device for retrieval of ovum and its associated follicular fluid.
2. Prior Art
Fertilization outside of the body is a process which offers women who are having difficulty in conceiving a child, a possible means of having a successful pregnancy. Essentially, an ovum or egg is removed from the perspective mother""s ovaries at the time of ovulation and is fertilized in a glass dish or test tube with the sperm from a male donor. This process of fertilization has four distinct components: ovarian hyperstimulation; ultrasound xe2x80x9cUSxe2x80x9d guided transvaginal ovum retrieval; actual in vitro fertilization and embryo maturation; and embryo transfer into the intrauterine cavity. In present practice, an ultrasound guided transvaginal ovum retrieval is accomplished by advancing a very long (36 inch) large bore needle through the posterior vagina, the cul-de-sac and into the peritoneal cavity. The proximal end of the needle is affixed with a fluid trap and is connected to a constant linear pressure suction device via a suction tubing. The suction initially xe2x80x9coffxe2x80x9d on entry into the peritoneal cavity through the cul-de-sac, because of a large volume of peritoneal fluid. The intent of the ovum retrieval is to isolate the follicular fluid and the ovum contained in it, within the fluid trap without spilling the follicular fluid into the peritoneal fluid and without contaminating the secured specimen with the peritoneal fluid. The fluid trap is blanketed with a small amount of IVF media that acts as a cushion to prevent ovum damage when the ovum is suctioned into the hard fluid trap. The current success rate in ovum retrieval is about a 90%. Some physicians will flush the deflated follicle with IVF media to attempt to increase the yields of the ovum retrieval to over 90%. Some physicians will flush the deflated follicle with IVF media in order to attempt to increase the yield of the ovum retrieval to over 90%.
The current practice of the ovum retrieval however, is cumbersome and requires at least four hands: the surgeon""s and an assistant""s. The mature follicle has a very friable thin wall, under tension by the pressure of the fluid therewithin. Ovum retrieval is usually scheduled 6 to 8 hours before the anticipated normal follicular rupture, or ovulation. When the sharp IVF needle, typical of the prior art, punctures the follicle, the follicular wall will tear and possibly release the ovum into the surrounding peritoneal fluid. Therefore, it is imperative that the puncture of the follicle with the distal tip of the IVF needle be simultaneous with the initiation of suction at the proximal end of the IVF needle. As the surgeon advances the IVF needle to penetrate the follicle, he/she directs the assistant to initiate suction at the fluid trap. When the follicle is completely deflated, he/she instructs the assistant to discontinue the suction. The fluid cap containing the follicular fluid and the ovum from a single follicle is disconnected from the proximal end of the IVF needle and suction source, and passed to the second assistant. All of these steps are completed as the surgeon controls the sharp needle within the patient""s peritoneal cavity as well as the ultrasound in the patient""s vagina. A new fluid trap is then attached to the IVF needle and suction is applied to retrieve the next ovum from the next mature follicle. It is typical practice to retrieve six to eight ova sequentially without removing the IVF needle from the peritoneal cavity or without removing the ultrasound probe from the patient""s vagina.
It is an object of the present invention to obviate the need of multiple assistants for the surgeon to facilitate ovum retrieval.
It is a further object of the present invention, to provide a method and apparatus that will more safely and more efficiently retrieve multiple ova from a patient.
The present invention comprises of an ovum retrieval apparatus as part of a system for the treatment of fertility conditions which includes the withdrawal of a gamete or egg from an ovary. The ovum retrieval device comprises a housing having a manually workable handle disposed off of one side thereof. The housing has an internal chamber with a forward wall. A long bore needle is arranged through the forward wall and has a proximal end within the chamber of the housing. The proximal end of the needle has a sharpened end thereon.
In one preferred embodiment of the present invention, a vacuum cartridge of generally cylindrical configuration is arranged within the chamber of the housing. The vacuum cartridge is arranged to sit on a slide member. The slide member is movable forwardly and rearwardly on a track arranged within the housing. The track is perpendicular with respect to the forward wall of the retrieval device. A trigger is connectively arranged to the slide member, adjacent to the handle, to permit advancement of the slide member and the vacuum cartridge carried thereon, forward or distally toward the proximal end of the long bore needle secured within the forward wall. The vacuum cartridge has a pierceable membrane on its first end to permit the proximal end of the long bore needle to pierce therethrough. The vacuum cartridge has a second end that may, in one embodiment, have a discharge valve, normally closed, therewithin. The discharge valve is adjacent a discharge port which port is in communication with the internal chamber of the vacuum cartridge. A cartridge-receiving notch may be arranged at the forward end of the slide, to snuggly receive and secure the vacuum cartridge therein. A biased pusher arrangement may be disposed between the perimeter of the first end of the vacuum cartridge and the inside edge of the forward wall of the housing retrieval device. The biased arrangement provides a rearward thrust to the slide member and the vacuum cartridge thereon.
The distal end of the long bore needle has a sharpened tip end thereon. An opening is arranged preferably within the sidewall of the needle adjacent to the sharpened tip end. The opening is in communication with a lumen extending the length of the long bore needle.
In a further embodiment of the present invention, the lumen of the long bore needle may have an arrangement of bumps, internal threads or the like to agitate any fluid passing therealong. In yet a further embodiment the needle may have a further therewithin for the carrying of an ultrasound probe, of the ultrasound probe may be slidably attached to the outerside of the needle shaft, to assist in the guidance and proper placement of the needle tip. In yet a still further preferred embodiment of the present invention, a pressurized rinse-fluid reservoir is arranged in communication with the needle tip, through a further lumen extending therethrough.
In operation of the present invention, the surgeon would pull the trigger on the housing so as to effect a forward motion to the slide member by a lever arranged between the trigger and that slide member. The forward motion of the slide member would effect a piercing of the membrane at the first end of the vacuum cartridge by the proximal end of the long bore needle. As the vacuum cartridge is being pierced, and a vacuum is being applied to the lumen of the long bore needle, the surgeon advances the sharp distal end, into a follicle to penetrate that follicle. The suction created by the piercable vacuum chamber would be non-linear and diminish during the process of the operation. This non-linear suction drawn procedure favors the capture of the ovum as the lumen of the long bore needle fills with follicular fluid, and the negative pressure becomes less within this system. The nonlinear suction may be used to separate the ovum and firmly attended cumulus from other cellular debris. The internal bumps or threads or a cochlear arrangement on the internal surface of the lumen may also be used to agitate the follicle fluid as it enters the ovum, so as to break up clumps of granular cells and strip non-firmly attached cumulus from the ovum. By virtue of the opening disposed on the sidewall of the distal needle tip, a tissue plug may be prevented from contaminating the follicle specimen, as may typically occur with sharp needles with front-tip openings. By virtue of the absence of tissue plugs, and the lack of large granular clumps of cells, this procedure permits the ovum to be separated from the rest of the follicular fluid by a simple gravity through the suspended granular cells. Separation of the ovum by simple gravitational forces would also circumvent the need for an embryologist to visually inspect the entire follicular specimen and to identify separate and isolate the ovum from the follicular fluid.
Once the vacuum cartridge has suctioned-in the ovum and follicular fluid, the trigger may be released to permit the biasing arrangement to push the slide member and vacuum cartridge rearwardly from the forward wall of the housing. The piercable membrane cover on the vacuum cartridge would be self-sealing, and permit the surgeon to remove the vacuum cartridge for further processing. The vacuum cartridge may then be taken to a processing or holding chamber, wherein the discharge port is placed through a penetrable membrane on the holding/processing chamber. The discharge valve may then be opened, to permit the follicular fluid and ovum to drain gravitationally into that processing/holding chamber for further treatment.
A yet further embodiment of the present invention includes the use of multiple vacuum cartridges in a rotary carousel. The carousel would be arranged with a plurality of parallel bores, each containing a vacuum cartridge. Rotation of the carousel to a new unused vacuum cartridge, in alignment with the long bore needle, would permit a sequential penetration of mature follicles for retrieving a plurality of ova thereby. The carousel would be supported rotatively, on a slide member in a manner similar to that of the aforementioned embodiment.
And yet a further embodiment of the present invention, the vacuum cartridges may be placed in a longitudinal manner, on an elongated slide member. Advancement and retraction of that slide member would make the utilization of a first vacuum cartridge, with its subsequent removal and permit rapid linear advancement of a subsequent cartridge forwardly on that slide member into engaging contact with the proximal end of the long bore needle.
Thus it has been shown a unique and efficient manner for the retrieval of an ovum from a follicle and an efficient and economical manner. The present retrieval apparatus permits the puncture of a follicle with the distal tip of the IVF long bore needle simultaneously with the initiation of suction at the proximal end of that needle.